The length of the arc making up 0.4 of a circle is equal to 37.68 cm Find the diameter of the circle.

To solve this problem, we introduce a conditional variable “X”, through which we denote the length of the entire circle.

Then, based on the data of the problem, we will compose the following proportion: 0.4 refers to 37.68 centimeters as 1 refers to X centimeters.

Then, based on this proportion, we make the following equation: X x 0.4 = 37.68 x 1.

Solving this equation, we get X equal to 94.2 centimeters.

Using the circle formula, we get a diameter equal to 94.2 / 3.14 = 30 centimeters.

Answer: 30 centimeters.